I seem to remember that the 747-400 that was involved in the Nairobi incident was G-BNLM. (I think)! If it is then its still currently flying for British Airways. I don't actually remember any of BAs 747-400 being removed from service after this incident. Perhaps one of BAs engineers can confirm and explain any tests that would have needed to be done.

While the intruder event happened, I have never, in years of working in BA Engineering, heard of one of our 747's being retired for any reason, aside from the reason most others airliners are retired.
Except B747-136 G-AWND, stranded in Kuwait as Iraq invaded in 1990, later used as an Iraqi army field latrine, as well as general vandalism before they torched it.
Or any aircraft being 'overstressed', the staff maybe, but not an aircraft!

Date: 29 DEC 2000
Type: Boeing 747-436
Operator: British Airways
Registration:
C/n / msn:
First flight:
Crew: Fatalities: 0 / Occupants: 19
Passengers: Fatalities: 0 / Occupants: 379
Total: Fatalities: 0 / Occupants: 398
Airplane damage: None
Location: Nairobi-Jomo Kenyatta International Airport (NBO) (Kenya)
Phase: En route
Nature: International Scheduled Passenger
Departure airport: London-Heathrow Airport (LHR/EGLL), United Kingdom
Destination airport: Nairobi-Jomo Kenyatta International Airport (NBO/HKNA), Kenya
Narrative:
During the flight, a 27-year old Kenyan man stormed the cockpit of the aircraft and tried to seize the controls of the aircraft. The autopilot was accidentally turned off as the crew struggled with the man and the aircraft lurched and made sudden manoeuvres. With the help of the passengers, the crew members overpowered the offender and regained control of the flight. Upon landing in Nairobi, six passengers were taken to hospital with injuries caused by the aircraft's violent movement.

Quoting 9MMPD (Reply 6):I have always wondered what is the reason that there is no G-BNLQ and G-CIVQ?

No British aircraft registration includes the letter 'Q' because of potential confusion with the letter 'O'. However the rest of the world seems to manage all right. Perhaps we Brits are just a shortsighted nation?

Quoting VV701 (Reply 7):No British aircraft registration includes the letter 'Q' because of potential confusion with the letter 'O'. However the rest of the world seems to manage all right. Perhaps we Brits are just a shortsighted nation?

Yeah but on the radio, one goes by the phonetic alphabet (although airliners use the airline callsign and flight number). Seems to me that the odds of confusion are probably low, the odds of say a G-ABCQ being alongside a G-ABCO on the same field being fairly low especially of both being the same type. As was pointed out, other countries seem to manage OK. I rented a PA28-140 registered C-FAQM for a while before I had my own plane.

SevenFourSeven, that will teach me to be flippant I guess!
To the point, no-one I know involved in BA 747 maint, from the shop floor to development Engineers, have ever mentioned anything about airframe overstressing, in this incident or any other.
Even beyond this group, had it happened, it would be well known in the airline and the subject of numerous threads here before now.

Quoting Airfoilsguy (Reply 16):There was an incident where a 747 got into a situation where it broke the sound barrier but it wasn't BA.

What incident was this? Source?

I had been under the impression that the only airliner that was NOT designed to be supersonic to ever fly supersonically in a controlled manner was a DC8-40 in a shallow dive during a test flight before delivery to Canadian Pacific. That was, of course, quite a while ago. Am I wrong?

Quoting BeechNut (Reply 14):the odds of say a G-ABCQ being alongside a G-ABCO on the same field being fairly low especially of both being the same type

Not in this case. There is a G-BNLO and a G-CIVO and both are BA 747 436s. If there were a G-BNLQ and/or a G-CIVQ - see Reply 4 - they too would be BA 747 436s. As all 57 of Ba's 747 436s are based at LHR and as most of their fleet fly out from mid morning to early evening and, excepting those on flights to Southern Africa and Australia, mostly return to LHR between early morning and mid afternoon on the following day, the chances of G-BNLO being alongside G-BNLQ or G-CIVO being alongside G-CIVQ at LHR on any particular day are not fairly low but actually quite high.

Quoting VV701 (Reply 7):No British aircraft registration includes the letter 'Q' because of potential confusion with the letter 'O'. However the rest of the world seems to manage all right. Perhaps we Brits are just a shortsighted nation?

Just as no US civil registration has an "I" (India) or "O" (Oscar) in it (to avoid confusion with the numbers 1 and 0...)